org.wicketstuff.offline.mode

Class OfflineCache

java.lang.Object

org.wicketstuff.offline.mode.OfflineCache

public class OfflineCache
extends Object

The offline cache to initialize / load the client side cache.

Example:

 
 List offlineCacheEntries = new ArrayList<>();
 offlineCacheEntries.add(new OfflineCacheEntry().setCacheObject(new CssResourceReference(HomePage.class, "main.css")));
 offlineCacheEntries.add(new OfflineCacheEntry().setCacheObject(HomePage.class));
 OfflineCache.init(this, "MyCache-1", offlineCacheEntries);
 
 

To contribute the offline cache use the following snippet in the renderHead method of a page:

 
 OfflineCache.renderHead(response);
 
 

If the cache name is going to be changed all resources are going to be reloaded again. This happens if the browser loads the new service worker content (after a browser refresh). The new service worker is going to be initialized as "waiting". (See chapter "How to Update a Service Worker" of the html5 rocks article) If you then switch the page to google for example and switch back, the new content is going to be shown up and the old service worker is going to be marked as "REDUNDANT". You have to leave the page with ALL tabs! Wicket handles older caches to be invalid and clear them - so when you switch from "MyCache-1" to "MyCache-2" all entries of "MyCache-1" are going to be cleared.

For more information see:

- https://www.w3.org/TR/service-workers/#navigator-service-worker-waiting
- https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API
- http://www.html5rocks.com/en/tutorials/service-worker/introduction/
- http://caniuse.com/#search=Service%20Worker
Important: local development can be achieved through HTTP (localhost, 0.0.0.0, 127.0.0.1), with DNS you have to use HTTPS! Service worker only running with HTTPS if not local.

Author:

Tobias Soloschenko

Constructor Summary

Constructors

Constructor and Description
OfflineCache()

Method Summary

Modifier and Type	Method and Description
static List<OfflineCacheEntry>	getOfflineCacheEntries(WebApplication application) Gets the offline cache entries
static void	init(WebApplication webApplication, String cacheName, List<OfflineCacheEntry> offlineCacheEntries) Initializes the offline cache (used in the init method of a wicket application)
static void	renderHead(IHeaderResponse response) Loads the service worker registration and the service worker implementation java script references
static void	setOfflineCacheEntries(WebApplication application, List<OfflineCacheEntry> offlineCacheEntries) Sets the offline cache entries (can only be used if the offline cache hasn't been initialized yet)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

OfflineCache

public OfflineCache()

Method Detail

init

public static void init(WebApplication webApplication,
                        String cacheName,
                        List<OfflineCacheEntry> offlineCacheEntries)

Initializes the offline cache (used in the init method of a wicket application)

Parameters:

webApplication - the web application to mount the offline cache references

cacheName - the cache name

offlineCacheEntries - the offline cache entries to be cached

renderHead

public static void renderHead(IHeaderResponse response)

Loads the service worker registration and the service worker implementation java script references

Parameters:

response - the response to contribute the offline cache references

getOfflineCacheEntries

public static List<OfflineCacheEntry> getOfflineCacheEntries(WebApplication application)

Gets the offline cache entries

Returns:

the offline cache entries

setOfflineCacheEntries

public static void setOfflineCacheEntries(WebApplication application,
                                          List<OfflineCacheEntry> offlineCacheEntries)

Sets the offline cache entries (can only be used if the offline cache hasn't been initialized yet)

Parameters:

application - the application instance

offlineCacheEntries - the offline cache entries to store